This invention is concerned generally with the use of multilayer ceramic substrates in connection with optical display devices and more specifically with the use of a liquid crystal cell display integrated into a multilayer ceramic substrate assembly.
Multilayer ceramic technology has been used in the prior art in connection with liquid crystal displays, e.g., in the manufacture of electronic watches. Typically, a ceramic substrate is used as an electrical interconnect vehicle between a liquid crystal display and one or more printed circuit boards mounted on a surface of the substrate. In these prior art displays, it is common to utilize a liquid crystal cell consisting of a pair of transparent conducting plates separated to form a cavity in which a liquid crystal material is contained. Elements of a display pattern are etched into both of the conducting plates. Displays of this type typically accomplish electrical connection between the ceramic substrate and the display pattern on the conducting plates through a number of conducting stripes, or access leads, also etched on the conducting plates. To eliminate unwanted electrical fields in regions of the liquid crystal in the vicinity of the access leads, it has been necessary to elaborately etch both the upper and lower conducting plates in such a way as to avoid undesired overlap of the electrical conductors. Very precise alignment of the two conducting plates is also required to avoid unwanted fields. For these reasons, it has been difficult to manufacture devices having complicated optical display patterns at reasonable cost.
Additionally, for some particular applications such as electronic wrist watches it would be desirable to have a display of greatly reduced thickness and increased ruggedness and reliability.